The whole idea of 'whereas an engine failure in the PC12 just means you look for a field straight away' is OK in good weather, and I have had the opportunity to avail myself of similar situations. However, it is the operation of single engine IFR over fog, poor terrain or at night etc and then when the donkey quits where do you look - your GPS?
Having nearly had to put my toe in the water after a break up of a cylinder going to Jersey many years ago making the front page of the Jersey Post for getting there is no comfort against two engines.
IFR flight with TV screens also needs back up steam driven systems to help in the event of failure (of which there seems to be a few).
My view for what its worth is that if the only justification of single engine IFR is cost or indeed 'I can because it has a turbine and they dont fail' (believe me they do!!) then its a pretty poor one.
I accept there is a risk in everything including twins, but if you cant fly a twin in an emergency you perhaps shouldnt be in one and that is surely the same arguement for a single? The real difference is that in a single you are commited to landing irrespective of the weather/conditions whereas hopefully in a twin (if you havent run out of fuel) you should have at least some options. If I had £2m plus to spend on a machine (which sadly I dont) would REALLY make me think twice about having only one engine.
